Dermoscopy

Three-point checklist CME

Created 2008.

Learning objectives

  • Describe and use the 3-point checklist for evaluating pigmented skin lesions by dermoscopy

Introduction

The dermoscopy 3-point checklist for early detection of skin cancer is fairly easy to learn and has a high sensitivity for melanoma. (1) There a high likelihood of malignancy (melanoma or basal cell carcinoma) if a pigmented skin lesion has any two of these criteria. The 3-point checklist has been designed to allow non-experts not to miss detection of melanomas. However, it is not as specific as pattern analysis (described in a later section).

  • Asymmetry: asymmetry of colour and structure in one or two perpendicular axes
  • Atypical network: pigment network with irregular holes and thick lines
  • Blue-white structures: any type of blue and/or white colour, i.e. combination of blue-white veil and regression structures

The main aim of the 3-point checklist is to determine whether the lesion being examined should undergo a biopsy. It does not an require accurate diagnosis to be made as the finer features of the lesion are not examined.

Symmetry

The following lesions demonstrate approximate symmetry of colour and structure. Shape is not considered.

The lesions below demonstrate asymmetry of colour or structure in one or two axes. Not all asymmetrical lesions are malignant.

Network

The following lesions are considered to have typical pigment network.

The lesions below have atypical pigment network, with irregular holes and thick lines (broadened network). Streaming or pseudopods would also be considered atypical. Not all lesions with atypical network prove to be malignant.

Irregular pigment network: black arrows to broadened network, asterisk to streaming

Blue-white structures

Blue-white structures can refer to any type of blue and/or white colour, i.e. combination of blue-white veil and regression structures, as shown in the following pictures. The colour can be subtle. Not all lesions with blue-white structures are malignant.

Activity

Practice dermoscopy, evaluating skin lesions using the 3-point checklist.

 

Acknowledgements

Online continuing medical education designed for health professionals and students.

Learning objectives will be listed for each topic.

Begin course 

Acknowledgements  

Developed in collaboration with the University of Auckland Goodfellow Unit in 2007.

Author: Hon A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, 2008.  

Images have been sourced from the following:

Course contents

  

 goodfellow unit logo

 

Related Information

References

  • Ref 1. Soyer P, Angenziano G, Zalaudek I et al. Three-point checklist of dermoscopy. Dermatology 2004;208:27-31. Medline.
  • Zalaudek I, Argenziano G, Soyer HP, Corona R, Sera F, Blum A, Braun RP, Cabo H, Ferrara G, Kopf AW, Langford D, Menzies SW, Pellacani G, Peris K, Seidenari S; THE DERMOSCOPY WORKING GROUP. Three-point checklist of dermoscopy: an open internet study. Br J Dermatol. 2006 Mar;154(3):431-7. Medline.

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